1. Field of the Invention
The present invention relates to an air cleaner for a vehicle, and more particularly, to a variable intake-type air cleaner that can actively control intake pressure performance in accordance with the RPM of an engine.
2. Description of Related Art
When foreign substances flow into the air that flows into an engine, they may cause problems, such as generating smoke and decreasing output, in addition to an engine trouble.
Therefore, the air flowing into the engine is allowed to flow inside after being filtered through an air cleaner. The air cleaner is equipped with a built-in filter and supplies purified air into the engine after filtering fine particles and foreign substances contained in the atmosphere.
Meanwhile, the structure of an air cleaner of the related art is shown in FIG. 1. An upper case 1 and a lower case 3 are combined such that air passes in one direction and a filter 5 that filters the air is disposed therein.
That is, an intake port 4 through which external air flows inside is formed at the lower case 3 and an exhaust port 2 through which the air filtered by the filter 5 is discharged is formed at the upper case 1.
Meanwhile, the engine of a vehicle is an internal combustion engine and the amount of air required for the engine depends on the RPM (Revolution Per Minute) of the engine. That is, a relatively small amount of air is required at a low RPM, but more amount of air is required at a high RPM.
However, flow resistance is generated while the air that is supplied to the engine flows not only the air cleaner, but an air hose connecting the air cleaner with a carburetor of the engine, such that loss of engine output may be caused, when the amount of air required for the engine is not sufficiently supplied.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.